1. Field of the Invention and Related Art Statement
The invention relates to an automatic analyzing apparatus for automatically analyzing biochemical samples such as blood and urine by measuring various kinds of substances contained in test liquid, i.e. a mixture of the sample and a reagent. There are suggested two types of automatic analyzing apparatus for analyzing such samples. One of them is a disposable type apparatus in which reaction vessels are disposed of from a reaction line every time one test liquid has been analyzed and new reaction vessels are changed therefor. The other one is a reusable type apparatus in which the reaction vessels set on the reaction line are used repeatedly by cleaning the reaction vessels after each analysis the test liquid.
When test items are to be analyzed by utilizing immunization agglutination reaction (hereinafter called as "immunization items"), the analysis is conducted by measuring the turbidity of the test liquid which becomes turbid by the antibody-antigen complex formed in the test liquid. The agglutinated antigen-antibody complex in the test liquid is apt to remain in the reaction vessel even if the reaction vessels are washed well. In addition to this, when measuring the turbidity of the test liquid containing the antigen-antibody complex, an S/N of an electric signal derived therefrom is so small that the agglutinated antigen-antibody complex remained in the reaction vessel affects a next analysis remarkably. Therefore, the disposable type analyzing apparatus is generally used for analyzing the immunization items.
On the other hand, in the reusable analyzing apparatus, the reaction vessels are used repeatedly by washing the reaction vessels every after each analysis operation. Therefore, it is very difficult to perfectly prevent the carry over of the test liquids in the reaction vessels. In order to prevent the carry over of the test liquid, it is necessary to provide many reaction vessel cleaning positions in the apparatus and/or to use cleaning material when washing the reaction vessels. Thus, the apparatus may become large in size and high in cost for analyzing.
When analyzing items to be analyzed by colorimetric method (hereinafter called "general items"), no agglutination occurs in the test liquid, and thus the test liquid is not apt to be carried over the reaction vessels after washing the reaction vessels. In addition to this, the signal-to-noise ratio (S/N) of the signal obtained by measuring the absorbency of the test liquid is so comparatively large that the carry over of the test liquid does not affect the S/N of the signal so much even if the test liquid is remained in the reaction vessels. If the disposable type analyzing apparatus is used for analyzing the general item, the cost for the reaction vessels becomes relatively high and thus the running cost for analyzing as a whole is increased. It also should be noted that the reagent for use in analyzing the general items is comparatively cheap, and thus the cost of the reaction vessel in the whole analyzing cost becomes high. For this reason, the reusable type analyzing apparatus is generally used for analyzing the general items.
Hitherto, these disposable and reusable analyzing apparatuses have been separately manufactured by maker and independently used by users. However, provided that the user have to provide these two type apparatuses separately, the cost for analyzing becomes high and a wide space for setting up the two apparatuses is necessary. Even if the disposable analyzing unit and the reusable analyzing unit are merely set up in one analyzing apparatus, the apparatus would become complex in construction and expensive in cost because two independent driving systems are necessary to drive the two reaction lines in the units.